Expandable web material having curvilinear structure

摘要

A slit web material has a curvilinear structure that is substantially longer than it is wide, with specially shaped slits, “tilde-slits”, which permit relatively easy expansion upon deployment. The cuts are arranged in continuous rows of tilde-slits. In any given row, the tilde-slits follow one-after-the-other in a curvilinear direction. Adjacent rows of slits are parallel to each other, but are offset from one another such that a line drawn between adjacent tilde-slits in adjacent rows is not perpendicular to the direction of the rows. The invention contemplates that the material dispenses from a continuous roll. If the slits are arranged in the longitudinal direction, then the web material expands in the width direction only upon deployment. However, if the slits are arranged such that the row direction is at some angle to the longitudinal direction, then the web material expands in both directions upon deployment. In this case, a special dispenser is not required, and the material expands in both directions as it is pulled off the roll prior to cutting a desired length of material from the roll.

主权项

1. A web material having a curvilinear structure including a longitudinal direction and dimension, a width direction and dimension, a top surface, a bottom surface, and at least two edges that are boundaries of the width dimension, said web material comprising a plurality of rows of tilde-slits, wherein:
a) the tilde-slits are cut extending from the top surface to the bottom surface; b) the tilde-slits are all congruent; c) each tilde-slit when unexpanded is a slit that consists essentially of:
two essentially parallel end portions separated by a center portion transverse to the end portions,the center portion further comprising a center point,wherein when a tensile force is applied on the web material the tilde-slits expand to form voids within the web material; d) each row of tilde-slits comprising a plurality of tilde slits wherein their center points all lie along a curved centerline having a degree of curvature or curve angle; e) the curved centerlines of the plurality of rows of tilde-slits are essentially parallel to each other; f) the end portions of the tilde-slits in a row are not parallel to the curved centerlines; g) the center point of any tilde-slit in a given row is positioned relative to the center point of the nearest tilde-slit in an adjacent row along a curved transversal intersecting the essentially parallel curved centerlines of the adjacent rows, wherein said transversal is not perpendicular to the essentially parallel curved centerlines; h) a second curved transversal extending coincident to said center point of the tilde-slit in an adjacent row and intersecting said transversal at an angle α to the longitudinal direction (x-axis), wherein the second transversal is not parallel to the longitudinal direction (x-axis) so that the tilde slit rows are offset; and i) when said transversal is extended in any direction, and thus intersects the essentially parallel curved centerlines of the adjacent rows, the center point of a tilde-slit will coincide with the intersection of the transversal with every essentially parallel curved centerline.